[PATCH v2 4/7] UBI: check max_beb_per1024 value in ubi_attach_mtd_dev

[Richard Genoud <richard.genoud@gmail.com>]

max_beb_per1024 shouldn't be negative, and a 0 value will be treated as
the default value.
For the upper bound, 768/1024 should be enough.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
---
 drivers/mtd/ubi/build.c |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index cc0a4fa..1ddced3 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -49,6 +49,9 @@
 /* Maximum number of comma-separated items in the 'mtd=' parameter */
 #define MTD_PARAM_MAX_COUNT 2
 
+/* Maximum value for the number of bad eraseblocks per 1024 limit */
+#define MAX_MTD_UBI_BEB_LIMIT 768
+
 #ifdef CONFIG_MTD_UBI_MODULE
 #define ubi_is_module() 1
 #else
@@ -855,6 +858,15 @@ int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
 	struct ubi_device *ubi;
 	int i, err, ref = 0;
 
+	if ((max_beb_per1024 < 0) || (max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT))
+		return -EINVAL;
+
+	/*
+	 * Use the default value if max_beb_per1024 isn't provided.
+	 */
+	if (!max_beb_per1024)
+		max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
+
 	/*
 	 * Check if we already have the same MTD device attached.
 	 *
-- 
1.7.2.5